I have a Horstmann Electronic 7 Maxistore water heater in my home and I've been having fuse problems as of late. We've been living here for about 7 months and never once had a problem but the other day I went to disconnect a storage heater and had to cut off the main power. When I turned it back on, the 15 amp fuse wire for my water heater blew. It was merely broken but I went out and got some new 15 amp fuse wire and replaced it. A few hours later I hear a loud pop and when I switched off the power and checked the fuse box the wire was completely gone except for the melted bits attached to the screws. Again I replaced it and again it happened. Fuse completely melted and gone. Is too much power flowing through? Is it safe to use a 30 amp wire? Any help would be much appreciated. Thanks